An electrically powered vehicle configured to be capable of generating vehicle driving power using a motor, such as an electric vehicle, a hybrid vehicle, or a fuel cell vehicle, is provided with a power storage device that stores electric power for driving the motor. In such an electrically powered vehicle, during starting or acceleration, electric power is supplied from the power storage device to the motor so as to generate vehicle driving power. On the other hand, during traveling on a downhill or deceleration, electric power generated by regenerative braking of the motor is supplied to the power storage device. Accordingly, the power storage device is repeatedly discharged and charged during vehicle traveling, so that control is required to manage a state of charge (hereinafter, also simply referred to as “SOC”) of the power storage device during the vehicle traveling. It should be noted that the SOC represents a ratio of a currently remaining capacity to a fully charged capacity. Generally, charging/discharging of the power storage device is controlled such that the SOC does not fall out of a predetermined control range.
As one manner of such SOC control for the electrically powered vehicle, Japanese Patent Laying-Open No. 2003-134602 (PTD 1) discloses a regenerative energy control device for a hybrid vehicle configured to store regenerative energy, which is generated during regenerative operation of the motor for driving, in a battery as electric energy. According to Japanese Patent Laying-Open No. 2003-134602 (PTD 1), when the battery cannot recover the regenerative energy, the motor for electric power generation is controlled to flow, in the motor for electric power generation, a d-axis current having a magnitude corresponding to the amount of regenerative energy that cannot be recovered by the battery. In this way, the excess of the electric energy can be recovered as heat loss of the motor for electric power generation.
Further, Japanese Patent Laying-Open No. 2009-196404 (PTD 2) discloses a hybrid control device configured to consume an excess of electric power using an air conditioning device, when electric power generated by regenerative braking of the motor exceeds permissible charging power for the battery.